It shall be lawful for the county commission of any county upon the application of the township board of directors, to empower and authorize the county highway engineer of said county, under the direction of the township board of such township, to survey, locate and plat the public highways of such township; and when such plat shall have been completed and approved by the township board, it shall be filed in the office of the township clerk, together with the minutes and report of such survey, to be kept by such township clerk as a part of his official records, the expenses of such proceeding to be paid out of the road fund of the township. The said plat, minutes and reports, or a certified copy of the same, over the hand and seal of the township clerk, shall be prima facie evidence that the road or roads therein contained or described have been constituted a public highway according to law.